On the evening of 30 September, 1975, a resident of Via Pola in Rome heard the muffled cries of a woman coming from the boot of a parked white Fiat. Inside, the police discovered Donatella Colasanti, 17, bloodied and battered, but alive, and the dead body of her friend, Rosaria Lopez, 20. Both had undergone hours of torture before Lopez was drowned in a bath. Colasanti had escaped the same fate only by playing dead.

The day before, the girls had accepted an invitation to the sea from three men Gianni Guido, Andrea Ghira and Angelo Izzo. Neofascists with a superiority complex, they had subjected the girls to a violent two-day ordeal at Ghiras villa before bundling their bodies into the Fiat. Look how well these dead girls are sleeping, Colasanti heard one of the men saying. They drove back to Rome and had gone to get pizza when the police were called. All three received life sentences, although Ghira managed to escape abroad his grave was supposedly found in Spain last year.

However horrific they may be, after a while most crimes that fill the front pages largely disappear from public memory. But an exhibition devoted to the cronaca nera of Rome at the Museo di Roma in Trastevere dusts off such forgotten scandals, showcasing 17 violent and brutal crimes committed in the capital between 1945 and 1991 with the aid of graphic images from police and press archives. Smiling back at you are the faces of the dead alongside crime scene photos showing them slumped on the floors of offices, homes or Roman pavements, sometimes covered with a sheet but often not. The photos that stick in the mind are those of bullet holes and bloodstains, of Maria Martirano Fenaroli, strangled to death in a summer dress on her kitchen floor in 1958 on her husbands orders, and of the swollen face of Donatella Colasanti, taken in the same moment the police opened the boot of the white Fiat in Via Pola.

There is no doubt that this is an intriguing exhibition, extensively researched and thoughtfully presented, but it also raises some uncomfortable questions. The public has always been simultaneously shocked and fascinated by horrific crimes and the motives behind them, but is morbid curiosity reason enough to turn real-life tragedy into a museum showpiece?

Gianni Borgna, political arts councillor for the comune of Roma who conceived the exhibition, argues that it is possible to tell the story of a citys evolution though its crime news. As an example he cites the murders of jewellers Gabriele and Silvano Menegazzo, shot in 1967 in one of the first robberies to be committed with firearms in Rome.

However, by filleting the bare facts of each crime from newspaper archives, the exhibition misses the opportunity to chronicle the way in which both crime reporting itself and public opinion have changed over the last 50 years. Once, the murder of a prostitute would have been big news: now it takes up three lines in the paper if theres room, comments journalist Enzo Rava, a consultant on the exhibition and author of Roma in Cronaca Nera. People have become immune to tragedy and crime, the reason being that they have access to all the fictional crimes imaginable on television and video.

It could be argued that the exhibition contributes to this desensitisation, compressing years of personal horror and grief into a 60-minute tour. But perhaps the real lesson to be learnt from the exhibition concerns the competence of the police: many of the crimes on display remain unsolved.

Roma in Nera. I Grandi Delitti tra Cronaca, Storia, Costume, Museo di Roma in Trastevere, Piazza S. Egidio 1b, tel. 0682059127. Feb 10-April 2.